Why is Java lying?

Hi,

I'm trying to compile a very simple JSP page on Tomcat 5.5, JDK 1.5

<%@ page import="java.util.*" %>
<%
        Object v = new String("b");
        session.setAttribute("a", v);

        Enumeration e = session.getAttributeNames();
        while (e.hasMoreElements()) {
                String attr = (String) e.nextElement();
                String v1 = session.getAttribute(attr);
                String v2 = session.getValue(attr);
                out.println("attr: " + attr + " v1:" + v1 + " v2:" +
v2);
        } // while
%>

but I'm getting this compile error:

An error occurred at line: 2 in the jsp file: /session_vars.jsp
Generated servlet error:
Type mismatch: cannot convert from Object to String

An error occurred at line: 2 in the jsp file: /session_vars.jsp
Generated servlet error:
Type mismatch: cannot convert from Object to String

    org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:512)
    org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:377)
    org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
    org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:802)

First off, the line number is incorrect (line 2 is "<%") but more
importantly, I thought String extended Object.

Any thoughts? - Dave